Room air conditioner

ABSTRACT

A room air conditioner of the character having a main section depending along an outside building wall below the building opening and with a duct section connected to the building opening, the main section including an upper room air section and a lower outside air section, the room air section including a pair of centrifugal fans disposed with their axes extending horizontally and located in the lower part of the room air section with the centrifugal fan housings oriented to provide an upblast disposition, the fan discharge being conveyed upwardly and forwardly through a pair of ducts having expanding end sections at the upstream face of an evaporator extending across substantially the entire width of the room air section and disposed in registry with the upper air passage of the duct section.

United States Patent [72] inventors Frederick S. Metcalfe Columbus;Edward M. Wuesthott, Worthington, both of, Ohio [21] Appl. No. 857,914[22] Filed Sept. 15, 11969 [45] Patented Aug. 31, 19711 [73] AesigneeWestinghouse Electric Corporation Pittsburgh, Pa.

[ 54] ROOM AIR CONDITIONER 8 Claims, 8 Drawing Figs. [52] [1.8. Ci62/262, 62/263 [5 i 1 Int. Cl JFZSd 23/12 [50] Field oi Search. 62/262,263 [56] References Cited UNITED STATES PATENTS 3,018,642 1/1962 Lathrop62/262 3,045,448 7/1962 Lauer. 62/263 3,404,539 10/1968 Laing 3,491,5491/1970 Oglesby Primary Examiner-William J. Wye AttorneysF. H. Henson andE. C. Arenz ABSTRACT: A room air conditioner of the character having amain section depending along an outside building wall below the buildingopening and with a duct section connected to the building opening, themain section including an upper room air section and a lower outside airsection, the room air section tending horizontally and located in thelower part of the room air section with the centrifugal fan housingsoriented to provide an upblast disposition, the fan discharge beingconveyed upwardly and forwardly through a pair of ducts having expandingend sections at the upstream face of an evaporator extending acrosssubstantially the entire width of the room air section and disposed inregistry with the upper air passage of the duct section.

PATENTEU M831 l9?! 3,602.006

SHEET 1 OF 4 VENTORS Fre S. Metcolfe 0nd Ed d M. Wuesthoff ATTORNEYPATENTED AUGBI I97! SHEET 2 OF 4 FIGS.

PATENTEU AUGBI l97l SHEET 3 [IF 4 FIG] PATENTEU AUEBI Ian SHEET 4 [IF 4ROOM AIR CONDITIONER CROSS REFERENCE TO RELATED APPLICATIONS Related US.patent applications are Ulich, Ser. Nos. 781,516, now US. Pat. No.3,548,611 and 781,517, now U.S. Patent No. 3,552,139 and Oberdier, Ser.No. 781,518, now US. Patent No. 3,543,533.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionpertains to the art of room air conditioners of the character which aremounted outside a building wall to depend below an opening therein andwhich have aduct section connecting the main section to the buildingopening.

2. Description of the Prior Art US. Patents of which we are aware andwhich disclose room air conditioners mounted substantially entirelyoutside of the room being conditioned and which includea casingdepending along the exterior of the building wall below an opening inthe wall are: 3,313,122; D-l79,726; 2,753,699; 2,737,788; 2,667,765;2,660,867; and 2,660,866, for example.

Outside mounted room air conditioners of the type which depend (i.e.,extend downwardly) along the outside of a building wall below a windowor other opening in the building provide a number of advantages ascompared to the typical window mounted air conditioner which hassubstantially no part depending below the bottom of the window. Suchadvantages are generally known and include such things as low noiselevel, limited obstruction of the viewing area of the window, and thepotential for a relatively high capacity rating without the increase inphysical size of the unit being observable from inside the room.However, to the extent that such units have been proposed as evidencedby the patents listed, and even with the substantial advantages afiordedby such units, they have not been commercially successful to any largedegree so far as we know.

For a room air conditioner to achieve commercial success underprevailing marketing conditions, a number of requirements should be metby the air conditioner. Among such requirements are that its cost becompatible with its capacity rating, that it be of a reasonable size forthe rating, that its performance characteristics be comparable withother room air conditioners of about the same cost, that it be of acharacter that it may be installed without undue difficulty in itsintended location, and that it be arranged to afford reasonablyconvenient servicing. The outside mounted room air conditioner withwhich this invention is concerned is one which is highly developed tomeet the requirements above, and holds the promise of capturing areasonable part of the market.

The room air conditioner unit according to this invention is, however,of a premium character in that it is relatively expensive as compared toother room air conditioners of the same capacity but which are of moreor less standard construction and do not include special features. Tojustify the purchase of an air conditioner according to the invention,it accordingly must possess some special advantages. One such specialadvantage is the relative quietness of the room air conditioner, whichis in part due, of course, to the main section being located entirelyoutside of the building, and in part to a low turbulence airflow pathfor the room air. Also the unit lends itself to creating a relativelylow profile as observed from within the room.

SUMMARY OF THE INVENTION Accordingly this invention deals generally withthe general structural arrangement of the main section, and inparticular with the structural arrangement of parts in the room airsection. Essentially, the room air section includes the same generalcomponents as found in the room air section of ordinary room airconditioners. 1n the upper or room air section of a unit according tothe invention, a pair of centrifugal fans are provided in the lowerportion of the section with the axes of the fans horizontal and parallelto the building wall, the fan housings for the fan being disposed in anupblast disposition, and duct means are coupled to the dischargeopenings of the fan housings to carry the discharged air from the fansup wardly and then forwardly into the area upstream of the evaporator,the duct means including expanding walls in this area so that theairflow from the fans will be distributed across the entire upstreamface of the refrigerant evaporator. The evaporator is located to extendacross substantially the entire width of the room air section and inregistry with an opening in the upper portion of the inner wall of theroom air section.

In accordance with a currently preferred embodiment of the invention,the duct means leading from the centrifugal fans to the evaporator is aformed, single piece (i.e., monolithic piece) which also includes theevaporator drip pan. The assembly of fan housings, duct means andevaporator pan serves in large part to separate the interior of the roomair section into the pressurized airspace for the air being forced tothe evaporator for conditioning, and the suction airspace through whichair is returned from the lower part of the duct section to the fans.

With the arrangement as described both the inlets to the fan housings,and the fan housing discharge openings lie in planes which are notperpendicular or normal to a line of sight looking directly through theduct section passages. This arrangement, coupled with the location ofthe evaporator relative to the fans, is believed to contributematerially to the relatively low noise rating of the unit.

DRAWING DESCRIPTION FIG. 1 is an isometric view of a room airconditioner according to the invention as viewed from outside thebuilding;

FIG. 2 is a side elevational view of the room air conditioner in mountedrelation to the building and with broken outlines illustrating thegeneral arrangement of the parts of the interior of the unit;

FIG. 3 is a partly-broken elevational view of the interior parts of theupper or room air portion of the main section with the wrapper or casingremoved;

FIG. 4 is a perspective view of the main section in assembled form andwith the wrapper omitted;

FIG. 5 is an exploded perspective view of the room side section;

FIG. 6 is a perspective view of the outside air section;

FIG. 7 is a vertical sectional view corresponding to one taken alongline 7-7 of FIG. 5; and

FIG. 8 is a perspective view of an installation in which the room airsection and outside air section are arranged in sideby-side relation.

DESCRIPTION OF THE PREFERRED EMBODIMENT The room air conditioner of FIG.1 is mounted with the main section 10 depending along the outside of abuilding wall 11, and with the duct section 12 coupled to the openingbelow the lower rail of a sash of an ordinary double hung or single hungwindow 113. While as shown in FIGS. 1 and 2 the unit is coupled to theroom being conditioned through a window opening, it will be appreciatedthat the unit may also be installed in a through-the-wall arrangement inwhich an opening is cut in the wall 1 l and the duct extendstherethrough into the room.

A typical lower story window mounting arrangement is shown in FIG. 2,the details with respect thereto, and also with respect to an upperstory mounting arrangement, being found in the noted Ulich patentapplication.

The main section 10 is of generally rectangular, box shape (rightparallelepiped) and includes an upper, room air section 115, and alower, outside air section 16 separated by a horizontal wall 17 whichsupports the main parts of the room air section.

The main section contains the refrigeration system components and theairflow components which together contribute most of the weight of theunit. The general locations of these components within the main sectionare designated by the dashline outlines in FIG. 2 and include arefrigerant compressor 18, condenser 19, and a condenser fan driven byelectric motor 21, all of these enumerated components being in the lowerpart of the main section, which has been termed the outside air section16, as illustrated. The upper, or room air section 15, of the mainsection is separated from the lower part by the noted wall 17 andcontains a pair of centrifugal fans 22 in scroll-shaped housings 23, thefans 22 being driven by oppositely projecting shafts of electric motor24 located between the fan housings. The fan housings 23 are disposed inan upblast disposition with the outlet 25 of each housing beingconnected by a duct 26 extending upwardly and then forwardly to deliverair from the fan to the upstream face 27 of the refrigerant evaporator28 which is located to extend across substantially the entire width ofthe room air section and is located in the upper, inner corner of thesection. The room air section is made weather tight and all of the wallsforming the section, save for the lower one, have thermal insulation ontheir inner faces. The lower wall has thermal insulation on its lowerface.

The duct section 12 comprises four outer walls and an intermediate wall29 to form a pair of open-ended passages 30 and 31,.which are theconditioned air, and return air, passages, respectively. The outer endof the duct section has its top wall flared upwardly and its bottom wallflared downwardly to define a total opening which registers with and isattached in substantially sealed relation to the open, upper, inner faceportion 32 of the room air section. The inner end of the duct sectionmounts an openwork decorative front and closure assembly 33 whichpreferably is of the general character disclosed in Appel U.S. Pat.application 685,698, now U.S. Pat. No. 3,476,033 and Ulich U.S. Pat.application 685,699, now U.S. Pat. No. 3,476,034.

As indicated by the arrows in FIG. 2, return air from the room passesthrough the room air passage 31 and into the room airspace of the mainsection by the fans 22. The fans draw the air into the housings andforce it through the duct work 26 to the expanded space plenum on theupstream side of the evaporator 28 from whence it passes through theevaporator and theconditioned air passage 30 of the duct section back tothe room. As noted in the Ulich 5I7 patent application, the duct sectionwalls are preferably of a material providing substantial thermalinsulation between the interior and exterior of the duct section, aswell as between the two passages in the duct section.

The arrangement of the components of the room air section and theirconstruction are probably best evident from-FIGS. 3-5. The room air fanmotor 24 is supported independently from the base wall 17 by a pair ofbrackets 34 (one shown in FIG. 5). Each fan housing includes a generallyflat bracket 35 disposed in an upright disposition and having a lowerflanged edge secured to the wall 17. The opposite sidewall and thescroll portion of the fan housing 23, in its currently preferred form,is a formed plastic member 230. The inlet openings to the housing inboth the bracket 35 and the formed plastic housing side are of equalsize. Also, while not wholly apparent in FIG. 5, the inlet openings ofthe housings facing the fan motor 24 are spaced sufficiently from theends of the fan motor to permit substantially unimpeded andaerodynamically smooth airflow into these inner openings. Also ofcourse, the openings facing the sidewalls of the main section are spacedsufl'rciently from the sidewalls to permit unimpeded flow into theopenings.

The plastic, formed scroll 23a is flanged along several of its edges, asat 36 for fastening the scroll to the upright bracket. It is alsoflanged along its top edge adjacent the cutoff 37 and along the side toprovide part of the base upon which the duct work will seat. It will benoted that both of the fan housings are formed in identical manner, andin each case as shown in FIG.

5 the upright bracket 35 is on the left and the scroll housing isfastened to the right side of the bracket.

The space for the electrical components such as motor startingcapacitors and terminal blocks, and the mountings therefor is providedby an upstanding, outwardly open channel 38 which is secured along itsbottom edges to the wall 17. A wiring harness 39 connects the controlbox 40 to the components mounted on the channel. The control box 40 isshown in FIG. 4 in its position for shipping, and is shown in itsoperative location accessible at the decorative front 33 in FIG. 2.

An opening 41 in the bottom wall 17 is provided with an. overlying cableoperated damper 42 to control the admission of outside air into the roomairspace.

In accordance with the currently preferred embodiment of the invention,the duct means 26 leading from the upblast discharge openings 25 of thefan housings is provided by a single-molded, plastic part which formsthe ducts for both of the fan outlets, as well as providing supportmeans for the evaporator 28 and the drip pan 43 for the evaporator. Asmay be seen in FIGS. 5 and 7, each duct 26 includes a curved rear andupper wall 44 and opposite sidewalls which include flat portions 45 andoutwardly flared forward portions 46 and 47 which provide a laterallyexpanding air passage as the air approaches the upstream face 27 of theevaporator. The single, formed member also includes a downwardlyinclined portion 48 (FIG. 7) located immediately forward of the locationof the cutoff 37 of the fan housings. The forward continuation of thisdownwardly inclined portion 48 constitutes the drip pan'43 with anupright lip 49 being formed on the front edge of the drip pan. A gasket50 is secured to the front face of the lip 49, and a slab of thermalinsulation 51 underlies the drip pan 43. At the forward edge of theflared portion 46 'of the duct means, a bracket portion 52 is providedto serve as a base for attaching the edge plates 53 of the evaporator,the formed member then continuing laterally at both sidesto block offthe space within which the return bends of the evaporator are located.The two flared inner wall portions 47 are connected by a flat portion 54to which is adhesively secured a rigid foam piece 55 which is triangularin horizontal section and serves as a continuation of the flaredportions 47 to prevent turbulence and noise. From the foregoingdescription it will be appreciated that the single, monolithic, memberwhich forms the duct means 26 for each fan also serves to support theevaporator, and to form the evaporator drip pan. Each of the duct means26 is expanded both laterally by the flared portions 46 and 47, as wellas downwardly by the wall 48 to facilitate the distribution of airacross the entire width and height of the evaporator 28 by the time theair reaches the upstream face 27 of the evaporator.

The top of the duct means is closed by the downwardly open, U-shapedouter wrapper (FIG. 1) which includes the top wall 56, and oppositesidewalls 57. The inner face of all of the walls of the wrapper areprovided with thermal insulation.

Referring again to FIGS. 3-5, a lower front wall 58 extends upwardlyfrom the front edge of the horizontal wall 17 forming the base of theroom air section. The top edge of this wall 58 serves to define thelower edge of the opening 32 defining the upper, inner face of the roomair section, and which is sized to be in registry with the outer end ofthe duct section 12. The side edges and upper edge of this opening 32Ais defined by the edges of the wrapper walls 56 and 57. The air filter59 (FIG. 4) extends for the entire width of the unit and from the lowersurface of the drip pan 43 down to the upper surface of the bottom wall17.

It will be appreciated from the foregoing that the space in the room airsection is basically divided, with respect to airflow, into thepressurized airspace on the discharge side of the fans and leading tothe evaporator, and the remainder of the space which constitutes allthat space through which air may flow in its way to the fans. In otherwords, the air is confined only in its way from the fans to theevaporator, with the remainder of the space simply serving to permit thereturn air to flow to the fans.

The arrangement of parts in the outside air section is illustrated inFIG. 6. The condenser 19 in that arrangement occupies the width andheight of the outer wall of the section with a louvered panel 60 (FIG.ll) overlying the face of the condenser. A formed shroud 61 with a fanring (not shown) is provided on the inner face of the condenser. Thecondenser fan 21 is mounted to the inner wall 62 of the outside airsection to properly locate the fan 20 within the ring. The compressor 18is mounted on the base wall of the outside section and to the side asillustrated in FIGS. 4 and 6. Both the electrical connections, and therefrigerant conducting line connections pass through the wall 17 at thebase of the room air section at appropriate locations as illustrated inFIG. 4.

The unit as assembled and with its wrapper on is mounted to a windowsillas shown in FIG. 2 in accordance with the details set forth in thefirst-noted Ulich patent application. Then, in accordance with thatapplication the duct section 12 is connected to the main section so thatthe outer open end 32 of the duct section registers with the opening onthe upper inner face of the room section. As such, the outer edge of theintermediate wall 29 seats against the gasket 50 on the front lip of theevaporator drip pan, while the lower edge of the outer open end of theduct section seals against a similarly placed gasket on the upper edgeof the stub wall 58. The side edges of the outer open end of the ductsection seat against the vertical edges of the wrapper, while the topedge of the duct section seats against the inner horizontal top edge ofthe wrapper.

The unit may also be installed in a through the wall arrangement inwhich a wall sleeve is provided and the main section is hung from asupport plate carrying brackets. The duct section is slightly modifiedin such an' installation, but the overall relation of main section andduct section is substantially the same.

In the embodiment shown in FIG. ll outside air is drawn into theopposite side louvers 63 of the wrapper and forced out through thelouvered panel 60. The airflow through the duct section and room airsection is as noted before.

The disposition of the fans as illustrated with their axes parallel withthe building wall and horizontal, and with the opposite side inlets andupblast discharge results in both the inlets and the fan dischargeoutlets lying in planes which are not perpendicular to a direct line ofsight from inside the room toward the unit. It is believed that thisarrangement contributes in part to the relative quietness of the unit inoperation. Also, the location of the evaporator in the path of thedischarge air but at the outer end of the duct section is be lieved toreduce air noise. Of course the duct section itself also contributes toa deadening of the noise.

Upon consideration it will be further appreciated that the provision ofthe room air section components supported independently upon its ownbase wall 17, and the outside air section components supported on thebase wall 17 and the front wall 62 lends itself to changing the basicconfiguration of the unit from one in which the room air section isstacked upon the outside air section, to one in which the sections aresideby-side. The only requirement of significance is to provide adifferent wrapper arrangement for each section, and to extend therefrigerant conducting lines and electrical lines between differentpoints. The use of an evaporator which is in the upper, inner corner ofthe room section results in the drip pan being situated above the bottomwall 17 of the room air section so that a gravity condensate drain maystill be used even though the room air section and outside air sectionare in sideby-side relation. The condenser airflow path may also bechanged when the sections are in side-by-side relation by providing theair openings in another part of the outside air section wrapper. Thus,in summary, the basic arrangement is not only eminently satisfactory fora unit in which the room air section and the outside air section arestacked on each other, but also lends itself to utilizing the sectionsin a modular fashion in which the sections are in side-by-siderelationship either inside or outside the building. An example of aside-byside arrangement in which the unit is coupled to an opening in abuilding wall rather than a window opening as illustrated in FIG. 8.Where the outer face of the outside air section is the only faceavailable for both the intake and exhaust of condenser air, that face isseparated into the two parts and the condenser is sized to occupy onlythe one part.

We claim as our invention:

l. A room air conditioner comprising:

a main section of substantially right-parallelepiped-shape containing anupper room air section, and a lower outside air section in stackedrelationship with each other and separated by a generally horizontalwall therebetween, said main section being adapted to be positioned inan upright disposition along the outside of a wall of the room to beconditioned, said upper room air section having at least the upperportion of its inner lface substantially open for the width of said mainsection;

a separable duct section connecting said open face with an opening insaid building wall, said duct section including an intermediate levelwall therein separating said duct section into a lower return airpassage, and an upper conditioned air passage;

said room air section including a pair of upblast-disposed, centrifugalfans located in the lower portion of said room air section inspaced-apart relation, and with their axes generally horizontal andparallel to said building wall, a refrigerant evaporator coil extendingacross the upper portion of the opening in said room air section, andfor substantially the entire width of said main section, the lower edgeof said coil being on a level substantially meeting the outer edge ofsaid intermediate level wall of said duct section; and

means in said room air section defining a passage from the outlets ofsaid fans to the upstream face of said coil.

2. A room air conditioner according to claim ll wherein:

each of said pair of said fans is of the double-inlet, scroll type, bothof said fans being driven by a single motor located between said fans.

3. A room air conditioner according to claim ll wherein:

said means defining said passage from the outlets of said fans to theupstream face of said coil comprises a separate duct section for eachfan connected to the upblast opening of each fan for confining theupwardly directed discharge of air from each fan and then turning ittoward the upstream face of said evaporator coil, each of said ductsincluding laterally flared end portions to expand the width of theairflow space to substantially the entire width of said evaporator coilat a location generally coincident with the upstream face of saidevaporator coil.

4!. A room air conditioner according to claim 3 including:

a condensate pan for said evaporator coil, said condensate pan and saidmeans defining a passage from the outlets of said fans to the upstreamface of said coil comprising a monolithic, formed section of a plasticmaterial.

A room air conditioner comprising:

a main section of substantially a rectangular box-shape comprising aroom air section and an outside air section, each of said sectionshaving a separate bottom wall dimensionally substantially equal to eachother, and a cubic size substantially equal to each other, and a cubicsize substantially equal to each other to accommodate selectivelyplacing said sections in stacked, and side-byside relation, said roomair section including means defining an opening located in the upperportion of the inner wall thereof;

duct means for coupling said room air section opening to an opening in awall of a building to be conditioned, said duct means including an upperconditioned air passage, and a lower return air passage;

said room air section including a pair of upblast-disposed, centrifugalfans located in the lower portion thereof in spaced apart relation andwith their axes generally horizontal and parallel to said building wall,a motor in said room air section for driving said fans, a refrigerantevaporator coil extending across the upper part of said opening in saidroom air section and for substantially the entire width of said room airsection, said evaporator coil substantially registering with said upperconditioned air passage in said duct means; and

means defining an expanding air passage between said centrifugal fansand the upstream face of said evaporator coil.

6.- A room air conditioner comprising:

a main section of substantially rectangular box-shape comprising a roomair section and an outside air section in stacked relationship, each ofsaid sections including an independent bottom wall of substantiallyequal rectangular dimensions, both of said sections being ofsubstantially equal cubic size, said room air section including meansdefining an opening located in the upper portion of the inner wallthereof providing an opening for communication of air between said roomair section and the room to be conditioned;

a duct section for coupling said room air section opening to an openingin a wall of a building to be conditioned, said duct section includingan upper conditioned air passage, and a lower return air passage;

said room air section including a pair of upblast-disposed, centrifugalfans located in the lower portion thereof in spaced apart relation andwith their axes generally horizontal and parallel to said building wall,a motor in said room air section for driving said fans, a refrigerantevaporator coil extending across the upper part of said room air sectionopening and for substantially the entire width, said coil being insubstantial registry with said upper conditioned air passage in saidduct section; and

means defining an expanding air passage between said centrifugal fansand the upstream face of said evaporator coil.

7. A room air conditioner according to claim 6 wherein:

said means defining said expanding air passage from said centrifugalfans to said evaporator includes integrally formed means for supportingsaid evaporator and providing an evaporator drip pan underlying saidevaporator.

8. A room air conditioner according to claim 7 wherein:

said centrifugal fans include scroll shaped housing means, each of saidhousing means includes an upright metallic wall of generally planar formhaving its lower edge secured to the bottom wall of said room airsection, the remainder of said scroll shaped housing essentiallycomprising a formed member supported solely from said upstanding wallforming an opposite side of said housing;

said means forming said expanded passageway and said evaporator supportand evaporator drain pan being supported by said fan housings and saidupright walls.

1. A room air conditioner comprising: a main section of substantiallyright-parallelepiped-shape containing an upper room air section, and alower outside air section in stacked relationship with each other andseparated by a generally horizontal wall therebetween, said main sectionbeing adapted to be positioned in an upright disposition along theoutside of a wall of the room to be conditioned, said upper room airsection having at least the upper portion of its inner facesubstantially open for the width of said main section; a separable ductsection connecting said open face with an opening in said building wall,said duct section including an intermediate level wall thereinseparating said duct section into a lower return air passage, and anupper conditioned air passage; said room air section including a pair ofupblast-disposed, centrifugal fans located in the lower portion of saidroom air section in spaced-apart relation, and with their axes generallyhorizontal and parallel to said building wall, a refrigerant evaporatorcoil extending across the upper portion of the opening in said room airsection, and for substantially the entire width of said main section,the lower edge of said coil being on a level substantially meeting theouter edge of said intermediate level wall of said duct section; andmeans in said room air section defining a passage from the outlets ofsaid fans to the upstream face of said coil.
 2. A room air conditioneraccording to claim 1 wherein: each of said pair of said fans is of thedouble-inlet, scroll Type, both of said fans being driven by a singlemotor located between said fans.
 3. A room air conditioner according toclaim 1 wherein: said means defining said passage from the outlets ofsaid fans to the upstream face of said coil comprises a separate ductsection for each fan connected to the upblast opening of each fan forconfining the upwardly directed discharge of air from each fan and thenturning it toward the upstream face of said evaporator coil, each ofsaid ducts including laterally flared end portions to expand the widthof the airflow space to substantially the entire width of saidevaporator coil at a location generally coincident with the upstreamface of said evaporator coil.
 4. A room air conditioner according toclaim 3 including: a condensate pan for said evaporator coil, saidcondensate pan and said means defining a passage from the outlets ofsaid fans to the upstream face of said coil comprising a monolithic,formed section of a plastic material.
 5. A room air conditionercomprising: a main section of substantially a rectangular box-shapecomprising a room air section and an outside air section, each of saidsections having a separate bottom wall dimensionally substantially equalto each other, and a cubic size substantially equal to each other, and acubic size substantially equal to each other to accommodate selectivelyplacing said sections in stacked, and side-by-side relation, said roomair section including means defining an opening located in the upperportion of the inner wall thereof; duct means for coupling said room airsection opening to an opening in a wall of a building to be conditioned,said duct means including an upper conditioned air passage, and a lowerreturn air passage; said room air section including a pair ofupblast-disposed, centrifugal fans located in the lower portion thereofin spaced apart relation and with their axes generally horizontal andparallel to said building wall, a motor in said room air section fordriving said fans, a refrigerant evaporator coil extending across theupper part of said opening in said room air section and forsubstantially the entire width of said room air section, said evaporatorcoil substantially registering with said upper conditioned air passagein said duct means; and means defining an expanding air passage betweensaid centrifugal fans and the upstream face of said evaporator coil. 6.A room air conditioner comprising: a main section of substantiallyrectangular box-shape comprising a room air section and an outside airsection in stacked relationship, each of said sections including anindependent bottom wall of substantially equal rectangular dimensions,both of said sections being of substantially equal cubic size, said roomair section including means defining an opening located in the upperportion of the inner wall thereof providing an opening for communicationof air between said room air section and the room to be conditioned; aduct section for coupling said room air section opening to an opening ina wall of a building to be conditioned, said duct section including anupper conditioned air passage, and a lower return air passage; said roomair section including a pair of upblast-disposed, centrifugal fanslocated in the lower portion thereof in spaced apart relation and withtheir axes generally horizontal and parallel to said building wall, amotor in said room air section for driving said fans, a refrigerantevaporator coil extending across the upper part of said room air sectionopening and for substantially the entire width, said coil being insubstantial registry with said upper conditioned air passage in saidduct section; and means defining an expanding air passage between saidcentrifugal fans and the upstream face of said evaporator coil.
 7. Aroom air conditioner according to claim 6 wherein: said means definingsaid expanding air passage from said centrifugal fans to said evaporatorinclUdes integrally formed means for supporting said evaporator andproviding an evaporator drip pan underlying said evaporator.
 8. A roomair conditioner according to claim 7 wherein: said centrifugal fansinclude scroll shaped housing means, each of said housing means includesan upright metallic wall of generally planar form having its lower edgesecured to the bottom wall of said room air section, the remainder ofsaid scroll shaped housing essentially comprising a formed membersupported solely from said upstanding wall forming an opposite side ofsaid housing; said means forming said expanded passageway and saidevaporator support and evaporator drain pan being supported by said fanhousings and said upright walls.